Feeding Bt (MON810) maize to pigs;Outcomes of the GMSAFOOD
project
M.C.Walsh1, S.G. Buzoianu1,2, M.C. Rea3, E. Gelencsér4,R.P. Ross3, G.E. Gardiner2, and P.G. Lawlor1
1Teagasc, Pig Development Department, Animal & Grassland Research & Innovation Centre,Moorepark and
3Teagasc Food Research Centre, Moorepark, Fermoy, Co. Cork, Ireland2Dept. of Chemical & Life Sciences, Waterford Institute of Technology, Waterford, Ireland
4Department of Biology, Central Food Research Institute, Budapest, Hungary
Outline
• GM Feed• Definition
• Ireland’s stance
• Authorisation of GM food in Europe
• Concerns with GM
• GMSAFOOD Project• Background
• Teagasc involvement
• Results of pig trials
• Conclusions
What is a GM feed?
• GMO are organisms in which the genetic material (DNA) hasbeen altered in a way that does not occur naturally (WHO, 2002)
• Transfer of desirable characteristics to living cells
• 0.9% established as the baseline for the ‘presence of GMO’
• Call for tolerance of 0.1% unauthorized GMO in animal feed
1. USA - 66.8 mill2. Brazil - 25.4 mill3. Argentina – 22.9 mill4. India – 9.4 mill5. Canada – 8.9 mill
• No cultivation of GM crops currently
• Only EU authorized GM crops can be imported
& used in animal production and for food
• Import large amounts of GM crops
(2005-2007; >3.4 million tonne imported into Ireland)
Ireland’s Position on GM Crops
EU Authorisation of GM feed• Based on EU regulation on genetically modified food and feed (829/2003)
• Application is made to member states
• Studies to show GM food is not dangerous to health or theenvironment
• Nutritionally equivalent to conventional counterpart
• Proposal for post-market monitoring
• Application forwarded to EFSA (6 mts to make decision)
• EFSA opinion submitted to the EC and member states
• EC and member states produce a draft of decision
• Submitted to ‘Standing Committee on the Food Chain and Animal Health’
• Decision different to EC – European Council of Ministers (90 days)
• Process can take up to 33 months
Concerns with GM• Perceived risk to health
• Development of toxicities and allergies
• Transfer of antibiotic resistance
• Environmental concerns
• Gene transfer to indigenous plants
• Reduced biodiversity
• Influence on non-target species
• Unintended responses may not appear until;
• Genetically diverse population
• Long period of time
Bt (MON810) maize
• Bt maize (MON810) – confers resistance
to the European corn borer
• Cry1Ab protein has been found todemonstrate antibacterial activity in-vitro(Yudina et al., 2007)
• To date, Cry1Ab protein has been provensafe in animal trials & no homology to anyallergenic proteins (EFSA, 2009)
32 male pigletsweaned at ~28 days
Non-GM maize(~39% of diet)
GM maize(~39% of diet)
• Penned individually in 4 similar rooms (8 pigs/room)• 31 day experiment (n = 10)
Short-term feeding of Bt (MON810) maize to pigs
Medium-term feeding of Bt (MON810) maize to pigs
72 male pigsWeaned ~ 28 d
Individually penned110 d study
12 d baseline period
Non-GM maizefed to slaughter
Trt. 1N = 10
GM maizefed to slaughter
Trt. 2N = 10
Non-GM maizefor 30 d/GM maize
to slaughter
GM maize for 30d/non-GM maize
to slaughter
Trt. 4N = 10
Trt. 3N = 10
• Growth performance• Organ structure and function• Intestinal histology• Intestinal microbial populations• Tracking of Bt toxin
Results
1. Growth Performance
0.110.5626.024.7d 30 BW, kg
0.280.0151.241.22FCE
0.03*22.9770697ADFI, g/d
0.1118.2620576ADG, g/d
P-valueSEGMNon-GMOverall
* P < 0.05
Short-term study
0.111.88108.6111.8105.8106.7d 105 BW, kg
P-valueSEGM/Non-GM
Non-GM/GM
GMNon-GMOverall
0.8625.91.951.981.961.96FCE
0.1845.51817190817731806ADFI, g/d
0.1618.3933961905920ADG, g/d
Medium-term study
Walsh et al., 2011
0.3817.98665.3690.0Liver, g
0.183.96142.2133.3Heart, g
0.142.7154.347.5Spleen, g
0.06†4.52161.0145.2Kidneys, g
P-valueSEGMNon-GM
† P < 0.10
No histopathological indicators of organ dysfunction
No changes in blood biochemistry indicative of organdamage
2. Organ FunctionShort-term study
Medium-term study
• No change in organ weight, structure or function following feeding GMmaize to pigs
No effect of short- or medium-term feeding of GM maize on villusheight or crypt depth in theduodenum, jejunum or ileum
No change in the number ofgoblet cells/villus in theduodenum, jejunum andileum in response to feedingGM maize
3. Intestinal Structure
4. Immune Response
0.000
0.400
0.800
1.200
1.600
2.000
1 10 100 1000
Non-GM GM Control
OD
45
0nm No antibodies specific
to the Bt toxin detected
IgA
• Elevated Th1 cytokine profile (inflammatory) in non-GMmaize pigs
• Non-GM maize-fed pigs may be exposed to more endotoxins
• GM maize-fed pigs may be protected from developing aninflammatory response due to the genetic modification in themaize (Walsh et al., 2011: PLoS ONE)
GMNon-GM
5. Intestinal microbiology
• Changes in the prevalence of a small number ofbacteria
• These bacteria were present in very low numbers
• Changes not likely to be detrimental to the pig
• Source of maize or differences in cultivars oringredients could potentially lead to similar subtlechanges
• Further work is being carried out in Moorepark
Short-term study
6. Fate of Bt toxin inside the pig
• No Bt maize toxin (DNA/protein) was found in the blood,heart, liver, kidney, spleen or muscle of pigs fed GM maize
• Bt toxin did not migrate from the digestive tract intoother organs
• Bt toxin is broken down as it progresses through the GIT
Genetic fingerprinting-Bt gene
ELISA-Bt protein
Bt maize
Conclusions
• GMSAFOOD project is still ongoing – due for completion inMarch 2012
• Bt maize has shown no adverse effects on;
• Growth performance
• Intestinal health
• Organ structure & function
• Bacteria in the digestive tract appear to tolerate Bt toxin
• Bt toxin does not migrate from the digestive tract & isbroken down as it processes through the tract
• Bt maize may offer protection against an inflammatoryresponse observed following non-GM maize consumption
Implications
• Feeding Bt maize resulted in no unintendedeffects when fed to pigs
• Can offer assurance to regulators, farmersand consumers as to the safety of Bt maize
Acknowledgements
Funding by the EU Commission 7th
Framework Programme under grantagreement n°211820 and the
Teagasc Walsh Fellowship Scheme